The University of Utah proposes to participate as a member of the Children's Cancer Study Group (CCSG) in the scientific design and execution of cooperative clinical research studies of childhood malignant neoplastic dieases. Utah's multi-disciplinary team of investigators have participated actively in CCSG for sixteen consecutive years. For more than a decade, Dr. Eugene Lahey led Utah's CCSG effort. In 1980, Dr. Richard O'Brien became Utah's CCSG principal investigator. He recruited a number of younger investigators with outstanding potential to supplement the experienced contributors to Utah's CCSG effort. Over the past three years Utah has aggressively enhanced its record of scientific and leadership contributions to CCSG. Dr. O'Brien, a member of the CCSG Late Effects Committee, is chairman of a proposed CCSG study (CCG-105N) expected to open for patient entry in April 1984, which will prospectively evaluate the neuropsychological effects of acute lymphoblastic leukemia (ALL) and its therapy. Dr. O'Brien is a member of a new, first line ALL study (CCG-105) and is also a member of two other new CCSG studies - Advanced Hodgkin's Disease (CCG-521) and Good Risk Medulloblastoma (CCG-923). Each of these studies address questions concerning possible late effects of therapy, an area of investigation in which Dr. O'Brien has special interest. Dr. Carl Kjeldsberg has joined Dr. John Wilson as major pathologists for CCSG lymphoma studies and they are responsible for "rapid review" of all NHL specimens. As a result, Utah serves as a Central Reference Pathology Laboratory for many of the CCSG lymphoma studies. In addition, their investigative work is defining the importance of histopathology in disease management. Dr. Dale Johnson is Vice Chairman of the Surgical Steering Committee, a member of the rhabdomyosarcoma study, a new relapsed ALL study (CCG-112) and has written the surgical guidelines for testicular biopsy for all ALL patients. Consequently, in the past three years under new leadership, there has been an impressive resurgance of Utah's scientific contributions to CCSG. Four Utah investigators are now key participants in more than half dozen new, first line CCSG studies, the results of which should be realized over the next few years. This recent record demonstrates the important role that Utah investigators play in the current and, particularly, the future scientific goals and accomplishments of CCSG.